1. Field of the Invention
The subject invention generally pertains to loading docks, and more specifically to a seal that seals against a dock leveler lip.
2. Description of Related Art
A typical loading dock of a building includes an exterior doorway with an elevated platform for loading and unloading vehicles, such as trucks and trailers. To compensate for height differences between the loading dock platform and an adjacent bed of a truck or trailer, many loading docks have a dock leveler. A typical dock leveler includes a deck, also known as a ramp or dockboard, which is pivotally hinged along its back edge to vary the height of its front edge. An extension plate, or lip, extends outward from the deck""s front edge to span the gap between the rear of the truck bed and the front edge of the deck. Depending on the particular dock leveler, some lips move linearly and others pivot between a stored position and an extended, operative position. In moving to the stored position, the lip usually retracts to where it does not interfere with a vehicle backing into the dock. In the extended, operative position, the lip extends from the deck""s front edge and rests upon the truck bed to form a bridge between the two. This allows personnel and material handling equipment to readily move on and off the vehicle during loading and unloading operations.
To protect the building and the dock leveler from direct vehicle impact, loading docks often include bumpers. Bumpers also help establish a predetermined distance between the rear of the vehicle and the dock leveler, so the dock leveler can first raise and then lower its lip upon the rear of the vehicle with a safe amount of overlap, or lip purchase, between the lip and the bed of the vehicle. Bumpers are usually installed near the bottom of the doorway, adjacent either side of the dock leveler lip and protrude a few inches out from the face of the dock, where they can be abutted by the rear of the vehicle.
To help block out rain, snow and outside air from entering the building through air gaps between the back of the vehicle and the exterior face of the building, usually either a dock seal or a dock shelter is installed around the perimeter of the doorway.
Dock shelters often have projecting members that protrude outwardly from the face of the building and run generally along the top and lateral sides of the doorway. From a protruding edge of the projecting members, a top extending member and two laterally extending members may extend inward and generally parallel to the building face to help seal against the truck""s top and sides, respectively. The laterally extending members are often made of a fabric or flexible foam. Two inner bottom corners of the dock shelter at the lower back sides of the truck are often partially sealed by draft pads attached to the lower ends of the projecting members. The dock leveler lip resting upon the rear of the vehicle is often relied upon to seal most of the doorway""s lower edge.
Typical dock seals comprise a resiliently compressible foam core protected by a fabric outer cover. They are usually mounted to the face of a building, along the top and both sides of the doorway. With dock seals, sealing is provided by backing the truck directly up against the seal. The seal then compressively conforms to the shape of the truck""s rear edges. The foam core provides the necessary compliance and resilience to repeatedly conform to the shape of various trucks, while the outer cover protects the foam core from dirt, water and abrasion. As with dock shelters, dock seals also rely on the dock leveler lip to seal most of the doorway""s lower edge.
With conventional dock seals and dock shelters, side clearance between the lip of the dock leveler and the inner side of each bumper creates areas that are difficult to seal off. Air gaps in these areas can cause a terrible upward draft into the building, particularly if the interior of the building is at a lower pressure than the outside air. The air gaps can be especially large for a dock leveler with a tapered lip whose width across the doorway is narrower along the tip or distal edge of the lip than along a proximal edge where the lip is hinged to the deck. Tapered lips create gaps that are similarly tapered (e.g., triangular or trapezoidal). Regardless of the air gap""s shape, sealing such openings can be difficult to do, because the lip must be able to move relative to the bumper. The lip not only needs to move between a stored and an extended position, but also needs to move vertically with the up and down pivotal movement of the dock leveler""s deck. Due to the difficulty of sealing the air gaps between a dock leveler lip and adjacent bumpers, such air gaps are known to be left open.
In some embodiments, a lip seal extends between a bumper of a loading dock and a lip of a dock leveler.
In some embodiments, a lip seal engages a bumper of a loading dock and a lip of a dock leveler.
In some embodiments, a lip seal engages the underside surface of a dock lever lip.
In some embodiments, a moveable seal member engages the bumper of a loading dock.
In some embodiments, a seal member is pivotal about an axis disposed underneath the deck of a loading dock.
In some embodiments, a seal member is adapted to engage a vehicle, the lip of a dock leveler, and the bumper of a loading dock.
In some embodiments, a seal member is able to seal a gap existing along a tapered edge of a dock leveler lip.
In some embodiments, a seal member for a dock leveler lip includes a compressible foam core with a pliable cover.
In some embodiments, a seal member includes a plurality of tabs adapted to engage an inside surface of a bumper.
In some embodiments, a seal member is adapted to engage the lip of a dock leveler over an area of contact that moves as the lip moves relative to the dock leveler""s deck
In some embodiments, a seal member is adapted to engage the bumper over an area of contact that moves as the pivotal deck pivots
In some embodiments, a spring urges the seal member to an operative position.
In some embodiments, a counterweight urges the seal member to an operative position.